The bicycles are welcomed to people not only for transportation but also for leisure activities. Along with the time for operating the bicycles increases, the safety for the cyclists are more concerned and the brake assembly for bicycles are directly related to the safety of the cyclists.
The conventional brake assembly for bicycles is connected to front fork or the seat stays, and generally comprises two arms and each arm has a brake pad connected thereto. The brake cable is connected to one side or the central portion of the arms so that the two arms are pivoted toward each other to allow the brake pads to contact the rim to stop the rim, such that the speed of the bicycle can be controlled.
For the brake cable connected to the central portion of each of the arms, the brake cables can be controlled by the cables or by hydraulic power.
Taiwan Utility Model No. 098209027 discloses a brake assembly which comprises two arms and a link, wherein each arm has a pivotal section which is connected with a pivot. Each arm has an installation section which extends from the underside of the pivotal section so that the brake pad is connected to the installation section. Each arm has a curved driven section which extends from the top of the pivotal section. Two resilient members are respectively connected between the bicycle and the arms to return the arms after braking. The link is located between the arms and has a contact face which contacts the two driven sections. The brake cable is connected to the center of the link so that the link is moved upward to push the connection portions of the two arms so that the arms are pivoted.
Taiwan Patent No. 101113861 discloses a brake assembly which comprises a first arm and a second arm, wherein each of the two arms has a top axial portion and a bottom axial portion. The top axial portion and the bottom axial portion are located in separate by a pivot. The bottom axial portion is used to maintain a brake pad, and the top axial portion is engaged with at least one hydraulic cylinder. The top axial portion of each of the right and left arms is connected to the at least one hydraulic cylinder by a wedge-shaped member. The hydraulic cylinder is located between the right arm and the left arm, and is designed to move the wedge-shaped member.
For Taiwan Utility Model No. 098209027, each arm has a curved driven section which extends from the top of the pivotal section, and the link is located between the arms and the brake cable is connected to the center of the link so that when the link is moved upward, the arms are pivoted by the movement of the link to brake the wheel. For Taiwan Patent No. 101113861, the hydraulic cylinder is located between the right arm and the left arm, and the wedge-shaped member is moved upward or downward when the hydraulic cylinder is operated so that the right arm and the left arm are pivoted to brake.
However, either of the two disclosures has longer distance between the brake cable and the link so that the operation force cannot transmitted directly, and this cause the braking force to be reduced. Besides, rollers are located between the arms and the link or wedge-shaped member, and the rollers increase the weight of the brake assembly. Furthermore, the driven sections and the link are easily stocked because of deformation due to the force applied thereto. When the situation is happened on one side, the two arms are not evenly operated to affect the brake efficiency and the rim is easily damaged. If the brake assembly is cooperated with the hydraulic cylinder, leaking of the hydraulic cylinder happens frequently, and the rod in the hydraulic cylinder shakes when the rod moves axially, this can also make the two arms to be operated unevenly. In addition, the hydraulic force is powerful and cab easily damage the parts of the brake assembly.
The present invention intends to provide a brake assembly which improves the shortcomings of the above mentioned conventional brake assemblies.